[PATCH v3 14/21] drm/sun4i: tcon: multiply the vtotal when not in interlace
From: Maxime Ripard <hidden>
Date: 2017-05-17 07:41:42
Also in:
dri-devel, linux-clk, linux-devicetree, lkml
Subsystem:
drm drivers, drm drivers and misc gpu patches, drm drivers for allwinner a10, the rest · Maintainers:
David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Chen-Yu Tsai, Linus Torvalds
It appears that the total vertical resolution needs to be doubled when we're not in interlaced. Make sure that is the case. Signed-off-by: Maxime Ripard <redacted> --- drivers/gpu/drm/sun4i/sun4i_tcon.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 62e254aedb57..a0f9a8a516c7 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c@@ -153,7 +153,7 @@ static int sun4i_tcon_get_clk_delay(struct drm_display_mode *mode, void sun4i_tcon0_mode_set(struct sun4i_tcon *tcon, struct drm_display_mode *mode) { - unsigned int bp, hsync, vsync; + unsigned int bp, hsync, vsync, vtotal; u8 clk_delay; u32 val = 0;
@@ -192,9 +192,26 @@ void sun4i_tcon0_mode_set(struct sun4i_tcon *tcon, DRM_DEBUG_DRIVER("Setting vertical total %d, backporch %d\n", mode->crtc_vtotal, bp); + /* + * The vertical resolution needs to be doubled in all + * cases. We could use crtc_vtotal and always multiply by two, + * but that leads to a rounding error in interlace when vtotal + * is odd. + * + * This happens with TV's PAL for example, where vtotal will + * be 625, crtc_vtotal 312, and thus crtc_vtotal * 2 will be + * 624, which apparently confuses the hardware. + * + * To work around this, we will always use vtotal, and + * multiply by two only if we're not in interlace. + */ + vtotal = mode->vtotal; + if (!(mode->flags & DRM_MODE_FLAG_INTERLACE)) + vtotal = vtotal * 2; + /* Set vertical display timings */ regmap_write(tcon->regs, SUN4I_TCON0_BASIC2_REG, - SUN4I_TCON0_BASIC2_V_TOTAL(mode->crtc_vtotal * 2) | + SUN4I_TCON0_BASIC2_V_TOTAL(vtotal) | SUN4I_TCON0_BASIC2_V_BACKPORCH(bp)); /* Set Hsync and Vsync length */
@@ -279,9 +296,9 @@ void sun4i_tcon1_mode_set(struct sun4i_tcon *tcon, /* Set vertical display timings */ bp = mode->crtc_vtotal - mode->crtc_vsync_start; DRM_DEBUG_DRIVER("Setting vertical total %d, backporch %d\n", - mode->vtotal, bp); + mode->crtc_vtotal, bp); regmap_write(tcon->regs, SUN4I_TCON1_BASIC4_REG, - SUN4I_TCON1_BASIC4_V_TOTAL(mode->vtotal) | + SUN4I_TCON1_BASIC4_V_TOTAL(mode->crtc_vtotal * 2) | SUN4I_TCON1_BASIC4_V_BACKPORCH(bp)); /* Set Hsync and Vsync length */
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